共查询到18条相似文献，搜索用时 62 毫秒
1.
河口分汊的定量表达及其基本模式 总被引：3，自引：0，他引：3
本文归纳出河口汊道间的四种交接方式:叉、合、结和口以及相应的十三种联线。并引入拓扑学中有关概念,定量表达点和线间关系。在分析河口汊道体系的拓扑学性质后,重新定义再结合因子,指出其与各种点和线、河口三角洲面积、河口汊道体系的外角等,均有一定的相关关系。在天然河口汊道体系中,最多出现的是点和口,其次是合和结;最多出现的线是fj,ff和fo,最少出现的是kk和ko线。最后,根据成因、形态和冲演特性相结合的原则,将河口分汉分成四个基本模式;少汊型、多汊型、河网型和游荡型分汊河口。并运用分汊河道体系的定量表示法,分析了各分汊模式河口汉道体系的拓扑学性质。 相似文献
2.
磨刀门河口沉积物粒度特征与沉积环境 总被引：4，自引：0，他引：4
磨刀门河口的发育深受地质构造和动力条件的制约，在河流和海洋的相互作用下，形成了复杂的沉积特征。根据磨刀门河口表层沉积物的粒度分析结果，运用数学地质方法对粒度参数进行多元统计对应分析，并在此基础上结合地貌和动力条件，分析河口的沉积物粒度特征及其动力沉积环境。结果表明，河口表层沉积物主要有粉砂质粘土、粘土质粉砂、极细砂、细砂等类型；沉积环境可划分为河口主槽沉积环境、涨潮流沉积环境、浅滩沉积环境、拦门沙坝沉积环境及河口前缘沉积环境。 相似文献
3.
4.
西汉古黄河三角洲初探 总被引：3，自引：1，他引：3
根据历史文献、地貌和第四纪地质调查以及卫星影象图等分析，探讨了西汉时期黄河河口位置、三角洲范围及其沉积特征。指出西汉古黄河三角洲的沉积特征与近代黄河三角洲相似，每年进入主河口的泥沙达２．７×ｌ０８ｔ左右。 相似文献
5.
珠江河口滩涂湿地的问题及其保护研究 总被引：19，自引：3，他引：19
珠江河口滩涂湿地是河口淤泥质淤长型湿地，它的自然特性和生态特点为河口生物资源多样性提供了生存和繁衍增殖的基础条件。随着珠江流域经济社会的发展，珠江河口滩涂湿地面积不断减少，同时还面临各种不可忽视的危机和问题。现以珠江流域水土资源开发利用和管理保护的视角研究珠江河口湿地保护的基本措施，建议加大依法保护河口滩涂湿地，科学利用滩涂湿地岸线，合理划分滩涂湿地的功能，动态研究河口湿地生态的发展，进一步保护河口湿地自然生态和生物多样性，使人与滩涂湿地和谐相处。 相似文献
6.
国外河口水文研究的动向 总被引：2，自引：0，他引：2
近十多年来,随着河口水文要素监测技术的现代化,物理和数学模型的不断完善,有力地推进了河口水文学的发展。本文从研究内容和研究方法两个方面对国外河口水文研究的动向进行了分析,着重介绍河口环流、河口锋、河口最大浑浊带研究的进展,并对现场观测、物理模型和数学模型等三种研究方法进行评价,可为发展具有我国特色的河口水文学提供借鉴。 相似文献
7.
黄河口近期环境演变与河口治理 总被引：4，自引：0，他引：4
本文分析了近几年来尾闾河道及河口滨海区实测资料，认为尾闾河道河相关系趋向于转好，河口变化造成的溯源冲淤作用影响范围仅有２０几ｋｍ，并且只有在汛期水流强度较大时，才发生溯源调整作用，非汛期淤积严重。由于河口砂咀向海凸出，三角洲前缘形成强流带，加上波浪作用及异重流发育，河口砂咀延伸速度明显减缓。最后，作者对目前河口治理中存在问题的解决提出了建议，尤其指出不应轻易放弃目前良好的河口行水环境。 相似文献
8.
本文通过对南渡江干流河口动力特征、河口过程的研究及历史海图的对比分析，揭示了该口门泥沙转运（或越过）的基本形式，阐述了在洪枯季条件下干流河口的地貌过程。 相似文献
9.
林雪美 《云南地理环境研究》1997,9(2):27-31
本研究以台湾西部３０个主次要河川的河口地区为研究对象，其河口堆积形态依堆积规模与位置，可概分为两岸沙洲型、左岸沙洲型、右岸沙洲型、没口沙洲型、扇状堆积型、宽阔滩面型及较少堆积型等七类。藉由定性比较与定量分析等方法，期以地形学的研究观点，达到了解河口地区地形特性、海陆交互作用与河口堆积形态之相关的目的，俾提供为河川下游平原开发利用之参考。 相似文献
10.
中国河口盐淡水混合特征研究 总被引：4，自引：0，他引：4
河口盐淡水混合受河口潮差、几何形态及淡水流量等诸多因素影响,并有着大小潮和洪枯季变化周期。本文在分析中国众多河口实测盐度分布资料的基础上,首次归纳了中国河口盐淡水混合的基本特征,给出数十个河口盐淡水混合的基本图式。并从高度分层型、部分混合型和强混合型三个类型,分别选择较典型的几个河口进行具体阐述。 相似文献
11.
长乐闽江河口湿地生态旅游开发研究 总被引：8，自引：0，他引：8
本文运用生态旅游的基本原理,阐述了长乐闽江河口湿地生态旅游资源的基本特征和开展生态旅游的重大意义,提出了长乐闽江河口湿地生态旅游的开发原则、开发思路以及可持续利用的对策。 相似文献
12.
Bed features were mapped using a thermal depth recorder and a side-scan sonar in the Changjiang (Yangtze) Estuary, and flows were observed and bed surface materials were sampled to investigate bed material transport pathways. Distinct scales and dimensions of dunes were observed in terms of the classification scheme of Ashley [Ashley, G.M., 1990. Classification of large-scale sub-aqueous bedforms: A new look at an old problem. Journal of Sedimentary Research, 61, 160–172], forming a dune set in the flood season. Large dunes occurred predominately in the surveyed area of the estuarine zone, and two-dimensional dunes predominated in the dry season while three-dimensional dunes prevailed in the flood season. Sharp lee sides of dunes have low angles, indicating a significant suspended-load transport for the bedform migration, and the majority of them face down-estuary reflecting the controlling process by the ebb current. The bed material migrations in terms of relative maximum gross transport show a satisfactory agreement with the sonar mapping in the dry season. The relative maximum gross transport as an independent estimator of migration direction, can be used to effectively determine the bed material transport directions in the Changjiang Estuary. 相似文献
13.
长江河口最大浑浊带研究 总被引：42，自引：1，他引：42
本文在以前一系列研究的基础上,把长江河口最大浑浊带视作一个系统,对它形成的环境背景、时空变化规律、泥沙来源、絮凝作用对悬沙落淤的影响、浮泥的特性与分布、悬沙的富集机制等进行了较系统的综合分析,并指出了需要深入研究的问题。 相似文献
14.
《The Professional geographer》1984,36(1):106-142
Book Reviewed in this article: Development and Environment in Peninsular Malaysia . S. Robert Aiken, Colin H. Leigh, Thomas R. Leinbach, Michael R. Moss. The Rural-Urban Fringe: Canadian Perspectives . Ken B. Beesley and Lorne H. Russwurm, eds. Women and Development . Lourdes Benería, ed. The Border that Joins: Mexican Migrants and U.S. Responsibility . Peter G. Brown and Henry Shue, eds. Cities of the World: World Regional Urban Development . Stanley D. Brunn and Jack L. Williams, eds. Time Resources, Society, and Ecology: On the Capacity for Human Interaction in Space and Time (Vol. I, Preindustrial Societies). Tommy Carlstein. Urban Geography . David Clark. Spanish City Planning in North America . Dora P. Crouch, Daniel J. Garr, and Axel I. Mundigo. Not On Our Street: Community Attitudes to Mental Health Care . M. J. Dear and S. M. Taylor Unequal growth: Urban and Regional Employment Change in the U.K. Stephen Fothergill and Graham Gudgin. Agricultural Land in an Urban Society . Owen J. Furuseth and John T. Pierce. The Petroleum Industry in Oil-Importing Developing Countries . Fariborz Ghadar. Historical Understanding in Geography, An Idealist Approach . Leonard Guelke. Regional Planning in Europe . R. Hudson and J. R. Lewis, eds. Remote Sensing for Resource Management . Chris J. Johannsen and James L. Sanders, eds. Geography and The State . R. J. Johnston. Texas Graveyards: a Cultural Legacy . Tlrry G. Jordan. The Politics of Location: An Introduction . Andrew Kirby. A Social Geography of the City . David Ley. Energy and the Future . Douglas MacLean and Peter Brown, eds. The Natural Environment of Newfoundland Past and Present . A. G. Macpherson and J. B. Macpherson, eds. Tourism: Economic, Physical and Social Impacts . Alister Mathieson and Geoffrey Wall. Railroads and Land Grant Policy: A Study in Government Intervention . Lloyd J. Mercer. Progress in Rural Geography . Michael Pacione, ed. Progress in Urban Geography . Michael Pacione, ed. Models of Spatial Inequality: Settlement Patterns in Historical Archaeology . Robert Paynter. Natural Hazard Risk Assessment and Public Policy, Anticipating the Unexpected . William J. Petak and Arthur A. Atkisson. The Nature of Geomorphology . Alistair F. Pitty. Regional Conflict and National Policy . Kent A. Price Women and Spatial Change: Learning Resources for Social Science Courses . Arlene C. Rengert and Janice J. Monk, eds. Urban and Regional Analysis for Development Planning . Richard Rhoda. Rivers: Form and Process in Alluvial Channels . Keith Richards. This Remarkable Continent: An Atlas of United States and Canadian Society and Culture . John F. Rooney, Jr., Wilbur Zelinsky, and Dean R. Louder, gen. eds. The Origins of Open-Field Agriculture . Trevor Rowley, ed. Residential Location Determinants of the Older Population . Gundars Rudzitis. Borderland Sourcebook: A Guide to the Literature on Northern Mexico and the American Southwest . Ellwyn R. Stoddard, Richard L. Nostrand, and Jonathan P. West, eds. Arctic and Antarctic . David Sugden. Tall Timbers Ecology and Management Conference, February 22–24, 1979, Proceedings No. 16 . Graphic Communication and Design in Contemporary Cartography (Progress in Contemporary Cartography , Vol. II). D. R. Fraser Taylor, ed. Living with Energy Shortfall: A Future for American Towns and Cities . Jon Van Til. The United States: Habitation of Hope . J. Wreford Watson. Air Photo Interpretation for Archaeologists . D. R. Wilson. Urban and Rural Change in West Germany . Trevor Wild, ed. Population and Resources . Harry Robinson. 相似文献
15.
<正>1 Introduction In 2013,Chagusaba,which is traditional tea-grass integrated system in Shizuoka,were accepted as new world heritage site of agriculture.Shizuoka prefecture occupies a variety of elevations,from 0 to 3000m or more above sea level.Because of the diversity of land features and climates,this area produces 167 agricultural commodities.In addition,a lot of traditional agriculture and over200 local native varieties of crops have been conserved in Shizuoka 相似文献
16.
MIN Qingwen 《资源与生态学报(英文版)》2014,5(4):289-290
<正>There are more than 10000 years of agricultural development history in the world that has provided very fruitful and ingenious traditional knowledge and experiences reflecting the evolution of humanity and the nature.In2002,the Food and Agriculture Organization of the United Nations(FAO)initiated an international partnership initiative of"Conservation and Adaptive Management of Globally Important Agricultural Heritage Systems 相似文献
17.
18.
《The Professional geographer》1984,36(2):250-283
Book Reviewed in this article: Geography and the Third World. International Seminar, 14–18 May 1980, Kuala Lumpur, Malaysia . Ishmail Ahmad and Jamaluddin Md Jahi, eds. The Growth Dilemma: Residents' Views and Local Population Change in the United States . Mark Baldassare. Sport and Place: A Geography of Sport in England, Scotland & Wales . John Bale. The Deindustrialization of America: Plant Closings, Community Abandonment, and the Dismantling of Basic Industry . Barry Bluestone and Bennett Harrison. Selected Essays 1963–1975: Carl O. Sauer . Bob Callahen, ed. Housing and Planning in the Countryside . G. Clark. Conflict, Politics and the Urban Scene . Kevin R. Cox and R. J. Johnston, eds. Thematic Maps: Their Design and Production . David J. Cuff and Mark T. Mattson. Wine: A Geographic Appreciation . Harm Jan de Blij. USSR in Maps . J. C. Dewdney. Political Geography: A Contemporary Perspective . Ramesh D. Dikshit. Rethinking Human Adaptation . Rada Dyson-Hudson and Michael A. Little, eds. Sacred Sands: The Struggle for Community in the indiana Dunes . J. Ronald Engel. Geography of the Biosphere . A. Furley and Walter W. Newey. Disaster and Reconstruction . Robert Geipel. Glasgow: The Making of a City . Andrew Gibb. Design for Arid Regions . Giden S. Golany, ed. Urbanization and Cancer Mortality: The United States Experience, 1950–1975 . Michael R. Greenberg. Geology in the Nineteenth Century: Changing Views of a Changing World . Mott T. Greene. Colonización y Destrucción de Bosques en Panamá . Stanley Heckadon Moreno and Alberto McKay, eds. Urban Geography: A First Approach . David T. Herbert and Colin J. Thomas. The Visual and Spatial Structure of Landscapes . Tadahiko Higuchi. Climate from Tree Rings . M. K. Hughes, P. M. Kelly, J. R. Pilcher, and V. C. LaMarche, Jr., eds. The structure of Nineteenth Century Cities . James H. Johnson and Colin G. Pooley, eds. The American Planner: Biographies and Recollections . Donald A. Krueckeberg, ed. Urban Land Policy For the 1980s, the Message for State and Local Government . George Lefcoe, ed. Regional Planning: Evolution, Crisis and Prospects . Gill C. Lim, ed. Relevance and Ethics In Geography . Bruce Mitchell and Dianne Draper. China: The Geography of Development and Modernization . Clifton W. Pannell and Laurence J. C. MA. The Urban Retailing System . Robert B. Potter. Hants. Nonconventional Energy Resources . Philip R. Pryde. Caribbean Migrants: Environment and Human Survival on St. Kitts and Nevis . Bonham C. Richardson. Population and Resources . Harry Robinson. East Los Angeles: History of A Barrio . Ricardo Romo. Integrated Impact Assessment . Frederick A. Rossini and Alan L. Porter, eds. Environmental Aesthetics: Essays in Interpretation . Barry Sadler and Allen Carlson, eds. Earthwatch . Charles Sheffield. Field Techniques and Research Methods in Geography . Robert H. Stoddard. Haiti: Land of Poverty . Robert J. Tata. Weathering and Erosion: Sources and Methods in Geography . Stephen T. Trudgill. Once Beneath the Forest. Prehistoric Terracing in the Río Bec Region of the Maya Lowlands . B. L. Turner, II. The Historical Geography of Scotland since 1707 . David Turnock. 相似文献